GF83.70-W-2000C | Starting heater operation, function | 17.10.97 |
MODELS 970, 972, 974, 975, 976 with CODE (H61) Webasto Air Top 2000 hot air auxiliary heater
MODELS 375.4, 944 with CODE (H61) "Webasto" Air Top 2000 hot air auxiliary heater
W83.70-0109-06
1 Heater unit
2 Heating air inflow vents
3 Combustion and heated air blower
4 Control IC
5 Flame sensor
6 Glow pin
7 Burner insert
8 Temperature limiter
9 Afterburner pipe
10 Heat exchanger
11 Fuel metering pump
12 Timer
13 Rotary potentiometer
A Exhaust
HA Heater outlet
HE Heater inlet
V Combustion air
Start heater operation
The heater's (1) heating operation is switched on manually or in the preselect mode using the heater's (1) timer (12).
The combustion and heated air blower (3) and the heating element (6) are started.
The combustion and heated air blower (3) runs for one second at 90 % maximum speed (breakaway torque) and is then regulated down to 30 %.
The aspirated heated air is routed past the temperature sensor:
- If the temperature of the aspirated heated air lies above the selected target temperature, then only the combustion and heated air blower runs (in control interval operating condition).
- If the temperature of the aspirated heated air lies below the selected target temperature, the starting procedure is initiated.
After approx. 20 seconds the fuel metering pump (11) starts up and fuel is delivered. A fuel-air mixture is formed in the afterburner pipe (9), which ignites at the heating element (6).
After another 25 seconds the speed of the combustion and heated air blower (3) is boosted to 60 % of maximum speed within 20 seconds and the fuel metering pump (11) is controlled proportional to this procedure. The temperature change alters the resistance of the flame monitor (5) and this then sends a corresponding signal to the controller board (4). The controller board (4) initiates stabilization of the combustion (see Stabilization).
If correct combustion does not take place within 120 seconds, where the heating element is switched on (6) and the fuel metering pump switched off (11) the speed of the combustion air and heated air blower (3) is increased and an automatic startup is repeated.
If combustion still does not take place, then after 80 seconds a malfunction cutoff takes place for 120 seconds with maximum speed with power-down of the combustion and heated air blower (3).
Stabilization
After another 20 seconds the speed of the combustion and heated air blower (3) is boosted to maximum speed within 17 seconds and the fuel metering pump (11) is controlled proportional to this procedure.
After 102 seconds the heating element (6) is switched off by the controller board (4).
If the flame goes out while being speeded up, the startup is repeated.
If stable combustion takes place, the auxiliary heater operates at maximum output.
Heat exchanger, location/task/design | |||
Heating element, location/task/design | |||
Flame monitor, location/task/design | |||
Timer, location/task/design | |||
Fuel metering pump, location/task/design | |||
Temperature limiter, location/task/design | |||
Combustion and heated air blower, location/task/design | |||
Controller board, location/task/design | |||
Burner insert with afterburner pipe, location/task/design |
Referenced documents
- gf8370w4017c Heat exchanger, location/task/design
- gf8370w4020c Heating element, location/task/design
- gf8370w4021c Flame monitor, location/task/design
- gf8370w4022c Timer, location/task/design
- gf8370w4023b Fuel metering pump, location/task/design
- gf8370w4026b Temperature limiter, location/task/design
- gf8370w4027b Combustion air/heated air blower, location/task/design
- gf8370w4028b Controller board for auxiliary heater, location/task/design
- gf8370w4029b Burner insert with afterburner pipe, location/task/design